The present invention relates to a sputtering target, a sputtering target-backing plate assembly and a deposition system capable of providing an inexpensive sputtering device by allowing for the power supply design of a sputtering device as a result of inhibiting changes in the voltage or current caused by the consumption of target during sputtering.
In recent years, self sputtering or high power sputtering for forming a uniform film on a via hole or a contact hole with a large aspect ratio pursuant to the miniaturization of wiring rules is becoming mainstream. Normally, since the circuit impedance will change pursuant to the target consumption in sputtering, maintenance of a uniform film thickness distribution and deposition rate throughout the entire lifespan of the target is sought by controlling the electrical energy to be constant.
Nevertheless, with the self sputtering and high power sputtering performed today, since changes in the current and voltage throughout the lifespan of the target are significant and a power source with an extremely large capacity is required, there is a problem in that the deposition system would become extremely costly.
Conventionally, for instance, Patent Document 1 and Patent Document 2 describe methods of processing the surface shape of the target in order to improve the film thickness distribution or reduce particles.
Nevertheless, very few reports refer to the fact that changes in the current and voltage of the sputtering device can be controlled with the surface area of the target. In addition, the current status is that there is no report that refers to the influence on the quantitative surface area.
[Patent Document 1] Japanese Patent Laid-Open Publication No. S62-37369
[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-84007